google service account authentication with google-api-php-client using calendar api - php

Question

i am using php 5.3.3, and codeigniter 2.1.0.
what i want to do is set up a service account, so a user can add an appointment in a text entry field on my website, then have that appointment added to a shared shared google calendar.
i have a google account, and using : https://code.google.com/apis/console I created a new project called 'pqp'
on services: enabled the calendar api
on api access: i created an oath 2.0 client id… product name = pqp, application type = service account.
downloaded the key 46… -privatekey.p12. there is a screenshot of the settings:
I got an svn checkout of the google-api-php-client (28/6/2012)
In the google-api-php-client/src/config.php I changed lines:
25: 'application_name' => 'pqp',
28: 'oauth2_client_id' => '373xxx730.apps.googleusercontent.com',
57: 'ioFileCache_directory' => 'tmp/apiClient', // my apache user does not have access to the system /tmp folder. + tmp/apiClient has permissions of 777 on the server.
using this link:
http://code.google.com/p/google-api-php-client/source/browse/trunk/examples/prediction/serviceAccount.php?spec=svn445&r=395
I modified it to:
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class Test extends CI_Controller{
function __construct()
{
parent::__construct();
}
function index()
{
set_include_path(get_include_path() . PATH_SEPARATOR .dirname(__FILE__).'/../libraries/google-api-php-client/src');
ini_set('error_reporting',E_ALL);
ini_set('display_errors','1');
// Set your client id, service account name, and the path to your private key.
// For more information about obtaining these keys, visit:
// https://developers.google.com/console/help/#service_accounts
define('CLIENT_ID','3731xxx44730.apps.googleusercontent.com');
define('SERVICE_ACCOUNT_NAME','373xxx244730#developer.gserviceaccount.com');
// Make sure you keep your key.p12 file in a secure location, and isn't
// readable by others.
define('KEY_FILE',dirname(__FILE__).'/../../461290xxx796c0b7db9582c-privatekey.p12');
require_once "apiClient.php";
require_once "contrib/apiCalendarService.php";
$client = new apiClient();
$client->setApplicationName("pqp");
// Set your cached access token. Remember to replace $_SESSION with a
// real database or memcached.
session_start();
if (isset($_SESSION['token'])) {
$client->setAccessToken($_SESSION['token']);
echo 'client access token is set.<br/>';
}
// Load the key in PKCS 12 format (you need to download this from the
// Google API Console when the service account was created.
$key = file_get_contents(KEY_FILE);
$creds = new apiAssertionCredentials(SERVICE_ACCOUNT_NAME,array('https://www.googleapis.com/auth/calendar'),$key);
$client->setAssertionCredentials($creds);
$client->setClientId(CLIENT_ID);
$service = new apiCalendarService($client);
echo 'client:<br/>';
var_dump($client);
echo 'service:<br/>';
var_dump($service);
// We're not done yet. Remember to update the cached access token.
// Remember to replace $_SESSION with a real database or memcached.
if ($client->getAccessToken()) {
$_SESSION['token'] = $client->getAccessToken();
echo 'token is good!, so creating an event....';
echo $this->insert_event($service,'testing summary','my location','2012-06-29T10:00:00.000+10:00','2012-06-29T10:00:00.000+10:00');
}
}
function insert_event($service,$summary,$location,$from,$to){
$event = new Event();
$event->setSummary($summary);
$event->setLocation($location);
$start = new EventDateTime();
$start->setDateTime($from);
$event->setStart($start);
$end = new EventDateTime();
$end->setDateTime($to);
$event->setEnd($end);
$attendee1 = new EventAttendee();
$attendee1->setEmail('test#example.com');
$attendees = array($attendee1);
$event->attendees = $attendees;
$createdEvent = $service->events->insert('primary', $event);
return $createdEvent->getId();
}
}
a pastie of the output is here:
the $client object is not authenticated, the getAccessToken is not set, and the event is not inserted.
i have found it difficult to work out which settings in the $config file to change because there is different nomenclature. i guess this is an artifact of how the code has progressed.
are the settings in src/config.php correct? do i need to alter any more settings?
it is my understanding that if i create the service account, download the key file, and the contents of this file with my developer id, it should return a token, and there is no need to set up a redirection uri.. is that correct? this is the functionality i want. i don't want the user to have to authorise access because the website will only ever interact with one google account.
So, the question is, how do i get this calendar api to authenticate using a google service account?

Answer 1

You can try this one if you not already...
EDIT: this one intresting but if you still feel like to write one yourself then try this THE mother of the oauth2. helpful
About Service Account at google-api-php-client that you use(always take the trunk's one with SVN) I can't found in that code manipulations any reference apiAssertionCredentials::generateAssertion()
definitely there is no call to auth in there
public function __construct(
$serviceAccountName,
$scopes,
$privateKey,
$privateKeyPassword = 'notasecret',
$assertionType = 'http://oauth.net/grant_type/jwt/1.0/bearer',
$prn = false) {
$this->serviceAccountName = $serviceAccountName;
$this->scopes = is_string($scopes) ? $scopes : implode(' ', $scopes);
$this->privateKey = $privateKey;
$this->privateKeyPassword = $privateKeyPassword;
$this->assertionType = $assertionType;
$this->prn = $prn;
}
and this method should be called I guess...
public function generateAssertion() {
$now = time();
$jwtParams = array(
'aud' => apiOAuth2::OAUTH2_TOKEN_URI,
'scope' => $this->scopes,
'iat' => $now,
'exp' => $now + self::MAX_TOKEN_LIFETIME_SECS,
'iss' => $this->serviceAccountName,
);
if ($this->prn !== false) {
$jwtParams['prn'] = $this->prn;
}
return $this->makeSignedJwt($jwtParams);
}
EDIT:
Pardon. In fresh ver. look's like it's Google_OAuth2::refreshTokenWithAssertion() actualy who should start the real proces